Diamonds and Rust Lyrics

Lyric discussion by dawnofvict0ry 

Cover art for Diamonds and Rust lyrics by Joan Baez

Baez has said before what "Diamonds and Rust" are: Memories. "Time turns ugly charcoal into diamonds and shiny metal into rust."

Still, could "memories bring diamonds and rust" refer to ancient or rather 10 years old mementos like cufflinks or half-shell turned to diamonds in rust rims?

@vphi I'm pretty sure that "the girl on the half-shell" refers to the image in Botticelli's painting "The Birth of Venus". She is saying that she was, or would have been, both mother (Madonna) and lover (Venus) to him. I think.